Telephone-switch-board plug



UNITED STATES PATENT OFFICE.

TELEPHONE-SWITCH-BOARD PLUG.

SPECIFICATION forming part of Letters Patent No. 325,952, dated September 8, 1885.

Application filed December 20, 1884. (No model.)

To all whom it may concern.-

Beit known that I, CHESTER KMEAD, a

citizen of the United States of America, and

a resident of the city of Des Moines, in the county of Polk and State of Iowa, have invented a new and useful Improvement in Tele-i phone-SWitch-Board Plugs, of which the following is a speeiiication.L

My object is to facilitate business and to" avoid the necessity of an operator at the switch-board at the exchange or central ofice from withdrawing his hand from the plug to lform a connection with a battery, as heretofore required, to close a circuit for the purpose of ringing a subscribers call-bell; and I accomplish the results contemplated by the device illustrated in the accompanying drawing, in which my improved plug is shown in position in a section of a switch-board as required to form a connection between a receiver at the exchange and a wire leading from the switch-board to a subscriber. f A represents a switchboard, and B a metal tube and conductor of common form fixed in the board. y, `c is a Wire leading to a subscriber from the rnd of the conductor B. d is a wire fixed to the same conductor by means of a post, f, to extend to and operate a visual signal on the face of the board A in a common way.

g is an elastic conductor fixed to the end of the conductorB in such a manner thatit will, in its normal condition, extend over and re# main in contact with the insulated post f, as required, to enable a subscriber to operate the visual signal when he calls tothe opcrator at the exchange. 1

h is a plug adapted to enter the tubular portion ofthe conductor B and to engage the free end of the spring g and to lift it from the contact-point of the post f, as required,fto open the circuit established with the visual signal and enunciator by means of the wire d and insulated post f. h is an or shoulder on the plug h, advance into the tube B. 7iis a second flange or shoulder. h is a tubular and open-ended annular flange extension of the plug and conductor h.

k is a tubular handle, made of nonfconducting material, into which the tubular part h of the plug is tted.

m is a coiled spring placed within the tuthat restricts its bular extension h in such a manner that in its normal condition it will press the plug outward relative to the tubular insulator and handle.

n is a conductor fixed to the end of the insulator and handle lc in such a manner that it will encircle the plug h between the flanges h and It, so that the plug can move longitudinally to alternately connect the two anges with the conductor n.

n is a branch extending from the conductor n through a groove in the surface of the handle to a metal ferrule and conductor, n,flxed on the end of the handlc,to form a connection with the transmitterstrip on the board in a common way.

r is a conducting-wire that extends from a `receiver through the ferrule n and a bore in the handle 7c to a screw, r', by means of which it is electrically connected with the conductor n, the plug h, and the wire c leading to a subscriber.

S is a conductor fixed against the end of the handle la in such a manner that it will encircle the tubular extension h of the plug and allow the flange h to come into contact therewith when the spring m is compressed by pressing thehandle k toward the board A, as required, to disconnect the plug from the conductor n and connect it with the conductor S.

Sis a wire that extends from a battery through a bore in the handle 7c to a screw, s, by means of which it is electrically connected with the conductor S, as required, to form au electrical connection with the plug h and the wire c for the purpose of ringing the subfscribers bell without withdrawing the hand from the handle la, and bysimply pressing the .handle toward the board A until the conductor S comes in contact with the flange 7L and out of contact with the conductor n.

From the detailed description of the construction and function of each element the unitary actions of all the parts and the practical operation of the complete invention will be obvious to persons familiar' with the prior state of the art.

I claim as my invention` l. An improved plug for telephone switchboards, composed of a tubular insulator and handle having a metal conductor ixed to its front end extended over the opposite end,and

IOO

a eo1iduetingwire combined therewith to eX- l a tulo'nlar extension, h, the tubular insulatend to a transmitting-strip on the board, a tor and handle 7c,having aspring, m, inclosed, condnetor xed to the rear end, and a Wire the fixed conductor n n n, having a Wire, 1^, combined therewith to extend to a battery, a attached, and the fixed conductor S, having 15 plug adapted to slide in the tubular handle awire attached, constructed, arranged, and and provided with two flanges or projections I Combined to operate in the manner set forth,

to alternately engage the two distinct-con for the purposes specified.

dnctors on the handle7 and a spring; to press CHESTER K. MEAD. the plug; outward relative to the tubular han- Witnesses: 1o die, for the purposes specified. THOMAS G. ORWIG,

2. The plug 7L, having (langes it and h/,and R. H. ORWIG. 

